1
/**
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 * @param {number[]} count
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 * @return {number[]}
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 */
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var sampleStats = function (count) {
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  let min;
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  let max;
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  let sum = 0;
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  let mode = 0;
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  let prefix = 0;
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  let prefixSum = new Map();
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  for (let i = 0; i < count.length; i++) {
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    if (count[i] === 0) continue;
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    if (min === undefined) min = i;
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    max = i;
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    if (count[i] > count[mode]) mode = i;
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    sum += count[i] * i;
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    prefix += count[i];
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    prefixSum.set(prefix, i);
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  }
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  const mean = sum / prefix;
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  // min, max, mean, mode found
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  // finding median using prefixSum map
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  let median;
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  let medianLeft;
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  let medianRight;
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  const medianPoint = Math.ceil(prefix / 2);
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  for (let i = medianPoint; i <= prefix; i++) {
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    if (!prefixSum.has(i)) continue;
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    if (medianLeft !== undefined) {
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      medianRight = prefixSum.get(i);
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      median = (medianLeft + medianRight) / 2;
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      break;
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    }
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    if (i === medianPoint && prefix % 2 === 0) {
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      medianLeft = prefixSum.get(i);
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      continue;
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    }
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    median = prefixSum.get(i);
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    break;
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  }
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  return [min, max, mean, median, mode];
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};